BMDshare is a brilliant website. I have posted many transcriptions of ancestors BMDs and a few unwanted BMD certs to help others.
I did register, was slighty confused with the 'Paid' membership and 'FREE'. Did have a mooch about and it all seemed a little too busy to take in and wasnt too sure where to post it, as I manage my own web design company found it all too busy and all too unclear. will go back later when have a bit more free time.
But yes its a good idea to post unwanted certs to help others
try here: you have to register but can add names and search stuff for FREE